1. Field of the Invention
The present invention relates generally to vehicular suspension systems and, in particular, is concerned with a hydraulically controlled stabilizer bar system.
2. Description of the Related Art
A vehicular suspension system typically consists of springs and dampers connecting the wheels to a body. These components support the mass of the vehicle and isolate the unevenness of the road surface from the passengers. The suspension system is also responsible for controlling the relative motion of the body to the wheels when actions such as braking pitch, turning roll and vertical road displacements heave create forces to the body.
For additional resistance to the lateral roll of the body that occurs during turning, a torsional spring known as a stabilizer bar is connected between the left and right corner suspensions of the car body. The stabilizer bar reduces the total roll angle while only moderately increasing the stiffness of the suspension system in heave or pitch directions. A stabilizer bar adds to the comfort of the passengers and improves the lateral stability and handling of the vehicle, and can be applied to either the front or the rear of the vehicle. When smaller roll angles and better handling are desired for a sporting type vehicle, the stiffness of the stabilizer bar can be increased such that the ride is significantly affected as a trade-off for handling.
Many stabilizer bars are U-shaped members having a central, transversely-mounted section and a pair of longitudinally-projecting arms connected to respective wheel supports, usually a control arm pivotally connected to a chassis rail. Oftentimes, either a rigid or flexible end link is connected between a control arm and a stabilizer bar. When the control arm moves as a result of a road input, the end link transmits all or part of the movement to the stabilizer bar. The spring effect of the stabilizer bar is then transmitted through an opposite end link to a control arm on the other side of the vehicle to resist the rolling motion of the vehicle.
The art continues to seek improvements. It is desirable to provide a stabilizer bar system having controllable hydraulic actuator connecting a stabilizer bar to a support to vary the roll resistance provided by the system.